a) x+4y=6 2x+y=5 x=6-4y 2(6-4y)+y=5 x=6-4y 12-8y+y=5 x=6-4y -8y+y=5-12 x=6-4y -7y=-7 |:(-7) x=6-4y y=1 x=6-4•1 y=1 x=6-4 y=1 x=2 y=1 b) x+y=7 2x+3y=15 x=7-y 2(7-y)+3y=15 x=7-y 14-2y+3y=15 x=7-y -2y+3y=15-14 x=7-y y=1 x=7-1 y=1 x=6 y=1 c) x+3y=8 2x+y=1 x=8-3y 2(8-3y)+y=1 x=8-3y 16-6y+y=1 x=8-3y -6y+y=1-16 x=8-3y -5y=-15 |:(-5) x=8-3y y=3 x=8-3•3 y=3 x=8-9 y=3 x=-1 y=3 d) x+3y=7 3x+4y=9 x=7-3y 3(7-3y)+4y=9 x=7-3y 21-9y+4y=9 x=7-3y -9y+4y=9-21 x=7-3y -5y=-12 |:(-5) x=7-3y y=12/5 x=7-3•12/5 y=2 2/5 x=7-36/5 y=2 2/5 x=7-7 1/5 y=2 2/5 x=-1/5 y=2 2/5 e) x-y=4 5x+2y=13 x=4+y 5(4+y)+2y=13 x=4+y 20+5y+2y=13 x=4+y 5y+2y=13-20 x=4+y 7y=-7 |:7 x=4+y y=-1 x=4+(-1) y=-1 x=4-1 y=-1 x=3 y=-1
Hejka miałam to ostatnio na matmie ;) a) x+4y=6 2x+y=5 x=6-4y 2(6-4y)+y=5 12-8y+y=5 -8y+y=5-12 -7y=-7 |:(-7) x=6-4y y=1 x=6-4•1 x=6-4 x=2 b)x+y=7 2x+3y=15 x=7-y 2(7-y)+3y=15 14-2y+3y=15 -2y+3y=15-14 x=7-1 x=6 c)x+3y=8 2x+y=1 x=8-3y 2(8-3y)+y=1 16-6y+y=1 -6y+y=1-16 -5y=-15 |:(-5) y=3 x=8-3•3 x=8-9x=-1 d)x+3y=7 3x+4y=9 x=7-3y 3(7-3y)+4y=9 21-9y+4y=9 -9y+4y=9-21 -5y=-12 |:(-5) y=12/5= 2 2/5 x=7-3•12/5 x=7-36/5 x=7-7 1/5 x=-1/5 e)x-y=4 5x+2y=13 x=4+y 5(4+y)+2y=13 20+5y+2y=13 5y+2y=13-20 7y=-7 |:7 y=-1 x=4+(-1) x=4-1 x=3 Mam nadzieję, że dobrze ;) pozdrawiam.
